A typical circuit board includes layers of conductive material (e.g., copper) and nonconductive material (e.g., fiberglass) sandwiched together to form a single, rigid board. Some circuit boards include many layers of alternating conductive and nonconductive materials.
In general, to manufacture a circuit board having multiple layers, a circuit board manufacturer creates separate circuit board sheets. Each circuit board sheet typically includes two conductive signal layers and a nonconductive separating layer disposed between the conductive signal layers. The manufacturer typically aligns multiple circuit board sheets along with other nonconductive sheets (e.g., nonconductive core layers) in an interleaved manner and laminates the sheets to form a single, integrated board.
A typical circuit board includes, as one of the signal layers, ground planes and power planes to provide power to the circuitry of the circuit board (e.g., circuit board components). A ground plane is a generally contiguous signal layer that carries a power supply ground signal (e.g., a reference voltage such as zero volts or chassis ground) from an external power supply to the circuit board circuitry. A power plane is also a generally contiguous signal layer that carries a power supply voltage signal (e.g., a DC voltage at a predetermined potential difference from the ground signal) from the power supply to the circuit board circuitry.
The typical circuit board includes, as one of the conductive signal layers, a data signal layer that carries data signals containing information for controlling the operation of the circuit board. Such a data signal layer typically includes conductive traces (e.g., data signal traces) that connect circuit board components mounted on the circuit board. Manufacturers conventionally include, as part of the data signal layer, conductive pads electrically connected to the conductive traces. The conductive pads provide a contact interface for a circuit board testing device, such as a bed of nails testing device. The conductive pads, therefore, allow a manufacturer to verify the integrity and continuity of the conductive traces of the circuit board (e.g., test for shorts in the conductive traces) prior to high volume manufacturing and shipping of the circuit board.
Certain conventional conductive pads electrically attach to a conductive trace by way, of conductive stubs. The conductive stub locates the conductive pad at a distance away from the conductive trace to provide a circuit board testing device access to the conductive pad. For example, assume a circuit board component is positioned in relative proximity to a conductive trace. A manufacturer utilizes the conductive stub to electrically connect the conductive pad to the conductive trace at a distance away from both the conductive trace and the circuit board component. The conductive stub, therefore, limits the circuit board component from interfering with a circuit board testing device's access to the conductive pad. Other conventional conductive pads electrically attach to a conductive trace via direct contact between the conductive pads and the conductive trace and without the use of a conductive stub. For example, conventional conductive pads are centered relative to the conductive trace.